They would have striked if the league didn't lock them out first. So what's the difference?

All the major leagues learned their lesson when the MLB agreed to continue playing under the old CBA, and then the MLBPA (under Fehr) went on strike right before the World Series.

The players might, or might not have struck. We'll never know. What is fact, is that the owners locked the players out. It's a bit unfair to say the players where were locked out also can't go find jobs elsewhere.